Early iPhone prototype: 5x7-inch display and serial port!?

An ancient Apple iPhone prototype from 2005 featured a massive 5x7-inch display, along with a number of connectivity options, including a USB port, ethernet jack and even a serial port.

The image below were obtained by Jacqui Cheng of Ars Technica via a source who used to work at Apple.

"At that early date no one knew what [the final device] would be," the former Apple employee told the publication. "It seems large now, but at the time it was really impressive seeing basically a version of OS X running on it."

As AppleInsider notes, the size of the prototype suggests the device may have originally been intended of as a tablet of sorts.

"I'll tell you a secret: It actually started with a tablet first," Jobs said at a 2010 AllThingsD conference. "I had this idea about having a glass display, a multitouch display you could type on with your fingers. I asked our folks, could we come up with a multitouch display that we could type on? And six months later they came back with this prototype display."

The RISC-based ARM chip powering the prototype is apparently a variant of the Samsung S3C2410, which Ars notes is a "distant relative of the chip the first iPhone ended up using, just older and slower."

Interestingly, the SoC was clocked at 200-233MHz, while the first 2007 iPhone used a 620MHz chip underclocked to 412Mhz.

"This chip is also an ARM9 chip, while the original iPhone eventually ended up using an ARM11 chip, but obviously Apple intended to use Samsung-manufactured ARM chips even this far back," Ars writer Andrew Cunningham added.